XII.—On Salpingostoma dasu: A New Carboniferous Seed from East Lothian

Abstract

In a recent paper (Gordon, 1938) reasons were given for the belief that semi-arid conditions prevailed during Lower Carboniferous times in the neighbourhood of North Berwick, East Lothian. The evidence was opposed, in a measure, to that advanced by Mr George Barrow in the East Lothian Memoir (1910) to substantiate the same position. He had relied on the absence of fossils as part proof; but, in point of fact, fossil plants have been obtained in abundance from the actual bedded ashes of Oxroad Bay that he considered (a) to be unfossiliferous, and (b) to have been formed in a manner similar to beds on the Springbok Flats of the Transvaal. The plants that have now been obtained showed xerophytic features, and, consequently, a semi-arid climate was proved on positive evidence. Other positive evidence of a lithological character was also presented in confirmation (Gordon, 1938, pp. 352, 353).

Reconstructing development of the earliest seed integuments raises a new hypothesis for the evolution of ancestral seed‐bearing structures

“…Isolated ovules of S. dasu presumably shed from C. scoticum cupules are larger than those still attached, reaching c . 50 mm long and 6 mm wide (Gordon, 1941). This correlation could indicate that ovules were shed from cupules at maturity (as implied by larger size).…”

“…10% fusion, through Genomosperma latens (Long, 1960a) with c . 25% fusion, increasing in Salpingostoma dasu (Gordon, 1941) to c . 33%, Physostoma elegans (Oliver, 1909) to c .…”

Early seed plant radiation: an ecological hypothesis

“…3). The nucellar apex is modified into a pollen chamber (Gordon 1941) closed by a pollen chamber floor and extended by a cylindrical structure (Hilton & Edwards 1996) referred to as a salpinx (Gordon 1941); the pollen chamber contains a central dome of parenchymatous cells. This combination of traits characterizes the hydrasperman reproductive syndrome (Rothwell 1986;Rothwell & Scheckler 1988).…”